Opposition Leader Bill Shorten has called on the Prime Minister to review proposed changes to Tasmania’s gun laws and consider intervening to stop them going ahead.

“I ask you to order an immediate review into the compliance of the Tasmanian Government’s proposal with the National Firearms Agreement,” Mr Shorten wrote to Malcolm Turnbull ahead of the return of Federal Parliament.

“If, as appears to be the case, that proposal would breach the agreement, I ask you to publicly demand that your Liberal Party colleagues in the Tasmanian Government abandon it.

“Simply put, the weakening of gun laws threatens the safety of our community.”

Tasmanian Premier Will Hodgman did not release plans for the changes in the lead-up to the March 3 state election.

They were made public on the eve of the poll, leading gun control groups to mount accusations of an attempted cover-up.

The proposed changes had been privately promised three weeks earlier to members of a firearms consultation group.

The Tasmanian government told the group that, if re-elected, it would allow greater access to category C firearms — such as self-loading rifles and pump-action shotguns — for farm workers and sporting shooters.

Licence holders in category C would also be allowed gun silencers.

Mr Hodgman has denied the stance would amount to watering down the gun controls brought in two decades ago after the Port Arthur massacre.

After being re-elected, Mr Hodgman said his government would not defy the national agreement on guns.

“We will engage with our colleagues on a national level to ensure there is no breach of the National Firearms Agreement,” Mr Hodgman said.

“It will not happen.”

Mr Hodgman said there would be an extensive consultation process before any legislation was put to the state parliament, and that the intent of the changes was to support farmers.

But Mr Shorten said he remained convinced the policy would be a backward step and the Federal Government should order a review.

“As Prime Minister, you cannot stand by and allow Australia’s world-leading gun laws to be watered-down,” Mr Shorten said in the letter.

“We only need look at the devastating, senseless tragedies occurring in the United States to know where this road leads.”